No abstract

Masonry is one of the oldest building construction methods used by man thousands of years ago, and one of those used today. The masonry buildings look stable and give a sense of security and comfort, leaving a lasting impression of strength. Shaking table tests are planned in order to deepen the understanding of the behaviour of confined masonry structures. This paper presents the observations from a series of shaking table tests done on a 1:1 scale confined masonry wall model without openings. The specimen was tested under constant gravity load and incrementally increasing in-plane loading seismic up to the occurrence of damage. The horizontal load applied is in-plane of the specimen. Then, the seismically damaged specimen was strengthened, using glass fiber reinforced polymers (GFRPs), and tested again. The specimen was strengthened on the surface of two sides. Hysteresis curves before and after with GFRPs wall strengthening are analysed. The tests results indicate that the GFRP system restores and increases the lateral load capacity of strengthened walls. Moreover, GFRP helps to increase the area of hysteresis curves, leading to increased seismic energy dissipation.

Shaking table tests are planned in order to deepen the understanding of the behavior of confined masonry structures with or without openings. This paper presents the observations from a series of shaking-table tests done on a 1:1 scaled confined masonry wall model without openings (model CMF). Frequency and stiffness changes before and after GFRP wall strengthening are analyzed. The main targets of this research are assessment of the influence of location and area of the opening on the load-bearing capacity, rigidity and ductility of confined masonry, definition of appropriate systems for improvement of the stiffness, load capacity and ductility of the system and contribution in the assessment procedures proposed for masonry building in Eurocode 8. The initial frequency of the undamaged model CMFuS is 24,63 Hz, while at the end of the testing, the frequency decreased to 10,60 Hz. This emphasizes the reduction of the initial stiffness of the model due to damage, especially in the masonry and tie-beam to tie-column connection. After strengthening of the damaged wall, the natural frequency increases to 19,78 Hz. This highlights the beneficial effect of the strengthening. After completion of dynamic testing at CMFS, the natural frequency is reduced to 12,48 Hz.